<?php 
header('Content-type:text/html;charset=utf-8');
class Hd{
	private $app = '应用';
	private $link = '连接';
	public function __isset($n){
		return isset($this->$n);
	}
}
$h = new Hd;
$bool = isset($h->link);
var_dump($bool);


 ?>